The Rise and Fall (?) of Shareholder Activism by Hedge Funds, by Brian R. Cheffins, University of Cambridge - Faculty of Law; European Corporate Governance Institute (ECGI), and John Armour, University of Oxford - Faculty of Law; Oxford-Man Institute of Quantitative Finance; European Corporate Governance Institute (ECGI), was recently posted on SSRN. Here is the abstract:

Shareholder activism by hedge funds became a major corporate governance phenomenon in the United States in the 2000s. This paper puts the trend into context by introducing a heuristic device referred to as 'the market for corporate influence' to distinguish the ex ante-oriented 'offensive' brand of activism hedge funds engage in from the ex post-oriented 'defensive' activism carried out by mutual funds and pension funds. The paper traces the rise of hedge fund activism and anticipates future developments, arguing in so doing that, despite the blow the 2008 financial crisis dealt to hedge funds, their interventions will remain an important element of U.S. corporate governance going forward.